Biliary heptatin agar is primarily used in microbiology laboratories for the selective isolation and differentiation of enteric pathogens, particularly Salmonella and Shigella species, from clinical and non-clinical samples. The medium contains bile salts that inhibit the growth of Gram-positive bacteria and many non-target Gram-negative organisms, allowing selective growth of pathogenic enterobacteria. The inclusion of specific carbohydrates and pH indicators enables differentiation based on fermentation abilities—colonies of Salmonella and Shigella typically appear colorless or pale, while lactose-fermenting bacteria like E. coli develop colored colonies. This makes biliary heptatin agar a valuable tool in diagnostic settings for identifying causative agents of gastrointestinal infections. It is commonly used in stool sample analysis and food safety testing to detect bacterial contamination.